Name:____________________________Date:____________Period:_______
3.1.3 Traffic River
Reflect and Apply
The City of San Antonio is currently receiving
bids on a contract to construct an over-pass for
the flow of traffic over a busy road. They have
selected your engineering firm to present a
model for the new bridge and have selected a
model similar to a bridge in the city of Dallas.
Your firm has presented the picture of a recent
bridge built. Because this bridge will be built at Loop 1604 and Blanco Road to help
the flow of traffic along Blanco road over 1604, your firm has also presented the
following modifications, along with the dimensions required.
Also, the length of
the
driving
lane
from left to right is
150 feet.
The length of
the main span
is 100 feet.
The maximum
height of the arch
should be of 16
Height from the
ground is 20 feet
to accommodate
the roads that
the bridge is
ft
connecting
Traffic
Bridge’s Driving Lane
Traffic
PART I Label the coordinates for the following points.
(
,
)
(
(
,
)
(
SATEC/Algebra II/Quadratic Functions/Introduction/Over Da Watta!(R&A)/Rev. 07-01
,
,
)
)
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PART II: Find the Equation of each of the following:
(a) The driving lanes (Remember the driving lanes is at ground level.)
(b) The vertical supports.
PART III: Information about the arch
(a) Is the parabola Concave Up/Down? ________________________________
(b) Will the parabola have a minimum or a maximum? Justify your answer.
__________________________________________________________
__________________________________________________________
(c) What does that tell you about the “a” value of the equation? Justify your
answer. ____________________________________________________
(d) What is the coordinate of the vertex? _____________________________
(e) How many roots are there for this problem? _____Do you have enough
information to find the coordinates? Justify your answer.________________
___________________________________________________________
(f) What is another point that is part of the parabola? ____________________
(g) What is the equation of the parabola? ______________________________
(h) Find the Roots for the arch. _____________________________________
(HINT: Set the function equal to zero!)
SATEC/Algebra II/Quadratic Functions/Introduction/Over Da Watta!(R&A)/Rev. 07-01
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